1. Field of Invention
The present invention relates to a thin film transistor and method of fabricating the same. More particularly, the present invention relates to a bottom-gate thin film transistor and method of fabricating the same.
2. Description of Related Art
In a conventional fabrication process of a bottom-gate thin film transistor (TFT), a microcrystalline silicon film is often formed on a gate insulating layer which is usually made up of silicon nitride, so as to solve the problem that the gate threshold voltage shifts and thus causes the display panel to have asymmetric brightness. However, since the characteristics of the microcrystalline silicon film and the gate insulating layer are so different from each other, the thin film interface between them has poor quality and easily becomes porous film or amorphous silicon film.
Specifically, when plasma enhanced chemical vapor deposition (PECVD) is employed to form the microcrystalline silicon film, the microcrystalline silicon film easily peels off because the microcrystalline silicon film and the silicon nitride film have a low level of adhesion therebetween. Moreover, the interface between the microcrystalline silicon film and the silicon nitride film does not has good crystallinity, so the overall microcrystalline silicon film accordingly will have poor crystallinity as well such that the characteristics of the thin film transistor deteriorate.